Transfer device



July 27, 1943. o. e. HAYES TRANSFER DEVICE Filed April 16, 1942 INVENTOR Patented July 27, 1943 TRANSFER DEVICE Oswald G. Hayes, North Hempsted, N. Y., assignor to Socony-Vacuum Oil Company, Incorporated, New York, N. Y., a corporation 'of New York Application April 16, 1942, Serial No. 4:9;180 5 Claims. (Cl. 214-17) This invention relates to means for transferring solids from one zone to another while substantially isolating the atmospheres of said zones and substantially avoiding crushing of the transferred solids.

In a number of industrial processes it is desirable to feed solids, in forms varying from fine powders to lumps and granules of definite or ir-' regular shape, from a source space to another space of an environment in respects such as temperature, pressure and gases present. vent intermingling of the atmospheres of the two spaces to a material extent, it is necessary to interpose some mechanical means often referred to as a valve which may or may not have a feature of accurate flow control. Such devices as star wheels, paired gate valves and others have been proposed. and extensively used for various purposes of this nature. Where crushing of the solids is not important as in feeding coal to a retort or ore to a furnace, known mechanisms have been fairly satisfactory.

However, in a number of instances, it is desirable to maintain the integrity of the individual particles to a substantial extent. A noteworthy example of this is the continuous catalytic cracking of hydrocarbon oils wherein a solid catalyst comprising pellets of clay or a synthetic alumina-silica composition are fed to a chamber through which the oil is passed in vapor form. The cracking operation rapidly deposits a carbonaceous contaminant on the surface of the pellets'which inhibits their cracking efficiency to such an extent that the catalyst becomes commercially impractical in a relatively short time, in some operations about 6 to 8 minutes. The catalyst is then purged of hydrocarbon liquids and vapors by the action of an inert 7 gas such as steam and/or vacuum, whereupon it is regenerated by burning ofi the carbon with preheated air and returned to the cracking chamber after another purging operation. Since the catalyst is usually conveyed through a space open to the atmosphere between cracking and regenerating chambers, it will be seen that a number of transfer devices of the type to which the invention relates must be included in a complete plant. The pellets are formed to an optimum size to present a large area for contact with hydrocarbon vapors while permitting relatively free flow through the catalytic mass. Crushing of the pellets is to be avoided asfull as possible.

The present invention contemplates a transfer device or valve adapted to the above purposes which permits transfer of pellets or other solid To pr forms between spaces isolated from each other while avoiding crushing to a substantial extent. The invention is further characterized by the reduction of attrition at relatively moving surfaces by handling the solids in such manner that I fine particles are restrained from entering be tween relatively moving parts of the device.

I These together with other objects and advan-{ tages of the invention will be apparent from the 'device embodying novel aspects of the invention;

Figure 2 is a view partially diagrammatic and partially in section of a possible modification of the feed end thereof;

Figure 3 is a diagrammatic showing of another form in which the invention may be embodied;

Figure 4 is a partial section on line 3-4 of Figure 3;

Figure 5 is a diagrammatic view illustrating third form of the invention which may also be regarded as a development of the device of Fi ure 3 in an advanced position; and

Figure 6 is a detail showing of a modification of the device of Figure 1 which is also adaptable to Figures 3 and 4. v

The device of Figure 1 is constructed to transfer solids from a hopper ill to a closed vessel ll through a conduit indicated generally at E2.

' The conduit and associated elements'form, in effeet, two series of chambers arranged for relative motion of the series with respect. to each other and adapted for communication of each chamber of one series alternately with each of two adjacent chambers of the opposing series. In the embodiment of Figure 1 there is a stationary series typified by chamber l3 formed in the walls of the conduit l2. The other series is defined by the walls of the conduit and reciprocating elements fitted therein such as the blocks l4 and I5. Preferably the blocks defining the tops and/or bottoms of the chambers of the reciprocating series move together, being joined as by rod l6 and operated by a connecting rod ll driven by a suitable source of power, not shown.

The upper surface of each of the blocks l4 and IS, the bottom of chamber l3 and all other.

municating space of lower level over a polished surface of a slope less than the extreme 811- gle of repose of the solid particles; but a slope at least equal to that angle is preferably given to these surfaces to insure adequate discharge.

As the reciprocating series is moved through a plurality of cycles it will be seen that material will be discharged from the upper surface of block I 4 into the chamber i3, completely clearing that surface ,if the material thereon is not in excess of the quantity which will be held by chamber l3, considering the angle of the upper surface of material so discharged to chamber l3. Assuming that the quantity above block I4 has not been excessive, the upward stroke of the reciprocating series will permit the edge of block for example, chamber I 3.

l4 nearest chamber l3 to contact the wall of conduit I 2 without crushing and/or shearing of solid particles.

As the upward stroke continues, the lower edge of block M will clear the bottom of chamber i 3 after the top has been closed to the conduit and the chamber i3 will discharge into the conduit below block i4. On the succeeding downward stroke the lower edge of the wall defining the bottom of chamber i 3 will pass the block II in the same manner as the block cleared in the upward stroke. Thus the solids may pass to and from a number (one or more) of chambers similar to l3 in the wall of the conduit in progressing downwardly by gravity without crushing and with a minimum of attrition due to solid particles between relatively moving parts.

The final discharge from the conduit l2 to the enclosed vessel ll may be direct through the conduit from the lowermost chamber similar to l3, but is preferably from, a final reciprocating chamber above block l5. At the low point of the downward stroke, block i5 moves out of contact with the walls of conduit 42 and discharges the material thereabove into the vessel Ii. By reason of the shape of its top portion, block I5 will normally re-enter conduit i2 in proper relation on the upward stroke, but it is preferable to provide guides to reduce vibration effects, such as the flanges l8 engaging slots in the sides of block IS.

The device is capable of transferring solid material downwardly through the conduit against a considerable pressure differential between vessel II and hopper iii. In a number of instances, however, it is desirable to inhibit'the passage of gases from the vessel ll upwardly through the conduit l2. For example, where vessel Ii is a catalytic cracking vessel, the hydrocarbon vapors may be prevented from contacting catalyst in the conduit to cause preliminary cracking accompanied by deposition of carbon at excessive rates due to long period of contact; and the vapors may be prevented from passing out to the atmosphere by the provision of an inlet IQ for steam or other inert gas. -When block l5 moves down to open communication between vessel 'ii and conduit l 2, the inlet I5 is uncovered permitting entrance of steam under a pressure somewhat in excess of the pressure in vessel ll, thus preventing flow of gases from vessel ll into conduit l2.

The steam inlet i9 may also be used to provide purging medium to displace gases included in the voids of the mass of solid particles. Such purging medium, such as steam, will move upwardly through the device gradually accomplishing the desired result before exhausting through-hopper in. This effect may, of course, be augmented by In .order to provide for a quantity of solids above block ll not in excess of that which can be discharged into chamber ii, there is provided means to deliver to the upper end of conduit l2 a limited quantity of solids from hopper It. In the embodiment of Figure 1, this is accomplished by the provision of a star wheel type of valve 20 receiving solidsfrom the throat 2| of the hopper iii. In order to avoid crushing of particles by the valve 20, the vanes of the star wheel are so proportioned to the walls of the valve that there is considerable clearance between relatively moving parts, preferably on the order of the greatest dimension of the particles or somewhat greater. The valve 20 is thus merely a restraining device wherein arching" of the mass of particles prevents any flow between vane and wall. Very satisfactory operation is obtained by intermittent rotation of the star wheel coordinated wth motion of rod I! in such manner that particles are restrained from dropping to the upper surface of block l4 after the upward stroke begins until the chamber I3 is closed to the upper part of conduit l2.

A very advantageous alternative to the valve 20 is shown in Figure 2. Where the solids are elevated from a lower level to enter the top of vessel ii, a bucket conveyor 22 or the like may be coordinated with the stroke of connecting rod l'l in such manner that solids will not be discharged onto block H at the time it is approaching the position to close chamber iii.

In Figures 3, 4 and 5 are shown modifications of the invention wherein relative motion of the parts is in a horizontal direction. In Figure 3 a core member 23 and an annular member 24 are mounted for relative rotary motion, Reference is made to Figure 5 as a development of the device of Figure 3 in an advanced position. Formed in the core 23 are a pair of chambers 25 having sloping bottom walls communicating with chambers 26 in the annular member. At a level below chambers 25 and adapted at their upper parts to communicate with the lower parts of chambers 26 are a pair of chambers 21 formed in the core 23 at an angular distance of from chambers 25. Still lower are chambers 28 in the annular member.

The upper chambers 25 are fed in a controlled manner, as described in connection with. Figures 1 and 2, with solid particles which pass downwardly through the series of chambers as members 23 and 24 are caused to have relative rotary motion with respect to each other.

Figure 5, in addition to being a development of Figure 3, may be regarded as illustrating diagrammatically a form of the invention wherein two fiat members having chambers 25, 26, and 21 are caused to reciprocate with respect to each other.

Where operation of the restraining means is not completely eifective or where for other reasons, there is a tendency for finely divided material to enter between relatively moving surfaces, a, wiper or brush 29 may be provided as shown in Figure 6 additional steam supply along the length of th and arranged with a space below to permit solids to fall from below the brush to chamber H, but any particles adhering to the wall of conduit I2, as by reason of static charges; are swept offand carried upwardly on the upward stroke.

Various modifications within the scope of the invention will be immediately apparent. For example, the reciprocating member of Figure 1 may be a core in a device generally similar to that of Figures 3 and 4 with the chambers of the core and annular member rearranged to suit or formed in continuous circles.

I claim:

1. In a device of the class described, wall means defining a substantially vertical conduit having atleast one chamber in communication therewith throughout the length of said chamber and formed with a bottom portion open to and sloping toward said conduit, a plurality of blocks closely fitting inside said wall means, means to reciprocate said blocks together longitudinally of said conduit, one of said blocks being associated with said chamber with its upper surface sloping toward said chamber and adapted to alternately place said chamber in communication with said conduit above and below said block as it recip rocates, one of said blocks being disposed for reciprocation below said chamber and adapted to alternately close and open the lower end of said conduit by motion into and out of said conduit, means to admit fluid to said conduit above said last named block when the lower end of said conduit is open and means to control the flow of olid matter to the upper end of said conduit.

2. In a device of the class described, wall means defining a substantially vertical conduit having at least one chamber in communication therewith throughout the length of said chamber and formed with a bottom portion open to and sloping toward said conduit, a plurality of blocks closely fitting inside said wall means, means to reciprocate said blocks together longitudinally of said conduit, one of said blocks being associated with said chamber with its upper surface sloping toward-said chamber and adapted to alternately place said chamber in communication with said conduit above and below said block as it reciprocates, and means to control the flow of solid matter to the upper end of said conduit.

3. In a device of the class described, wall means defining a substantially vertical conduit'having at least one chamber in communication therewith throughout the length of said chamber and formed with a bottom portion open to and sloping tpward said conduit, a plurality of blocks closely fitting inside said wall means, means to reciprocate said blocks together longitudinally of said conduit, one of said blocks being associated with said chamber with its upper surfacesloping toward said chamber and adapted to alternately place said chamber in communication with said conduit above and below said block as it reciprocates, one of said blocks being disposed for reciprocation below said chamber and adapted to alternately close and open the lower end of said conduit by motion into and out of said conduit.

4. In a device of the class described, wall means defining a substantially vertical conduit having at least one chamber in communication therewith throughout the length of said chamber and formed with a bottom portion open to and sloping toward said conduit, a plurality of blocks closely fitting inside said wall means, means to reciprocate said blocks together longitudinally of said conduit, one of said blocks being associated with said chamber with its upper surface sloping toward said chamber and adapted to alternately place said chamber in communication with said conduit above and below said block as it reciprocates, one of saidblocks being disposed for reciprocation below said chamber and adapted to alternately close and open the lower end of said conduit by motion into and out of said conduit, means to admit fluid to said conduit above said last named block when the lower end of said conduit is open, a wiper extending along the lower edge of the upper surface of said block associated with said chamber and means to control the flow of solid matter to the upper end of saidconduit.

5. In a device of the class described, wall means defining a substantially vertical conduit having at least one chamber in communication therewith throughout the length of said chamber and formed with a bottom portion open to and sloping toward said conduit, a plurality of blocks closely fitting inside said wall means, means to reciprocate said blocks together longitudinally of said conduit, one of said blocks being associated with said chamber with its upper surface sloping toward said chamber and adapted to alternately place said chamber in communication with said conduit above and below said block as it reciprocates, one of said blocks being disposed for reciprocation below said chamber and adapted to alternately close and open the lower end of said conduit by motion into and out of said conduit and means to admit fluid to said conduit above said last named block when the lower end of said conduit is open.

OSWALD G. HAYES. 

